This application claims the benefit of the priority date of U.S. provisional patent application 60/533,247, filed Dec. 31, 2003.
The present invention relates generally to the field of ion exchange chromatographic materials in the context of separation science and analytical biochemistry.
The increasing need for bulk quantities of biologically relevant molecules (i.e., biomolecules) such as proteins has spawned a variety of techniques for isolating such biomolecules from physiological isolates. Traditional techniques in this regard include precipitation methods, electrophoretic separations, and membrane filtration. One of the more promising separation methodologies advanced, however, is liquid chromatography.
Chromatographic separations of complex biomolecules typically require one or more modifications of the sample that contains the biomolecules. The interactions between biomolecules and a chromatographic sorbent include electrostatic attraction and repulsion, ion exchange, hydrophobic associations, charge transfer, and van der Waals attraction. These forces often compete with each other to impose a delicate balance between conditions that are suitable for a biomolecule to adsorb onto a chromatographic sorbent and those conditions under which the biomolecule may desorb. Difficulties can arise when sorbents are in the presence of highly ionic solutions (such as concentrated sodium chloride) or in the presence of strong acids or bases. It is desirable to have sorbents that can be functionality-modified and still provide an effective sorbent surface, under various ionic and pH condition.
Accordingly, a continued need exists for improved ion exchange-chromatographic materials that exhibit high binding capacity and, in particular, that can be modified to change functionalities, and that are effective under different pH and/or ionic strength conditions.